1. Technical Field
Example embodiments of the present invention relate in general to a tree model and forest model generating method and apparatus, and more specifically to a method and apparatus for generating three-dimensional (3D) tree and forest models using tree photos and terrains.
2. Related Art
Natural objects such as trees, forests, and the like are very important elements as background contents of films and games. The related technologies may be roughly divided into two such as a three-dimensional (3D) tree model generating field and a 3D forest model generating field.
First, the 3D tree model generating field may be roughly divided into three conventional methods such as a rules-based tree modeling method, a user interactive tree modeling method, and an image-based tree modeling method.
First, a procedural method such as an L-system and fractal method or the rules-based tree modeling method generates repetitive tree skeletons using rules defined in advance or randomized variables of branch position function values. Such a rules-based tree modeling method is a classical method in generating a tree model, and has been widely used because it enables complex tree model generation through setting of less variable values. However, the rules-based tree modeling method has limitations such as difficulties in controlling the overall appearance of a tree and generating a tree having a user's desired shape.
Second, the user interactive tree modeling method is a 3D tree model generating method through a user's 2D sketch, and generates a tree model based on a producer's drawing including tree shapes and branch shapes. The user interactive tree modeling method is more user-intuitive compared to the existing rules-based tree modeling method, but has limitations that it requires a lot of efforts and proficiency of a user (or content producer) when generating a complex tree.
Third, the image-based tree modeling method is a method of generating a 3D tree model through image matching and an object structure restoration method using a plurality of pieces of tree images as inputs, but has an inherent accuracy problem in the methodology itself and requires a lot of manual labor in tree segment and skeletonization within images.
U.S. Pat. No. 7,917,346 relates to simulation in which branches spread from a tree trunk to a fixed specific position below a tree crown, and has very limited problems in realistic tree modeling and self-growth representation.
In addition, U.S. Pat. No. 5,224,179 relates to skeletonization of an object within an image, and extracts a skeleton of the object within the image by scanning templates defined in advance to the object. However, this has problems such as difficulties in accurate skeleton extraction of objects having high complexity with much noise of deformation and protrusion such as trees.